The purification of wastewater or other fluids can be accomplished by the use of membrane packs. Feed fluid such as waste water, is applied under pressure to the outside of the membrane packs. Pure water passes through membranes of the packs into a porous carrier of the packs, and from there to a permeate outlet. The feed fluid, minus some pure water, is disposed of through a concentrate outlet.
It has been found highly advantageous to produce some or all of the pressure of the feed fluid through centrifugal force, by mounting the membrane packs in the chamber of a rotary frame that is rotated at high speed. U.S. Pat. No. 4,132,649 by Croopnick et al describes a purification apparatus of this type. In such an apparatus, a stack of membrane packs is trapped between top and bottom plates held together by bolts, with one plate rotatably mounted on a first bearing and connected to a feed conduit passing through the first bearing, and the other plate rotatably mounted on a second bearing and connected to a concentrate conduit extending through the second bearing. Pure water, or permeate, flies out through the periphery of the rotor to a shroud which gathers it. While such an arrangement can securely rotatably support the rotor, it has been found that such an arrangement can make maintenance difficult.
In actual use of the above-type of purification apparatus, access to the chamber of the rotary frame is required at relatively frequent intervals. For example, a commercial centrifugal purification apparatus may include numerous stacked membranes, and it is possible for a membrane to develop a leak that allows mixing of concentrate and permeate (brackish water and pure water), which requires immediate replacement of the failed membrane pack. In the development of membrane packs, especially for purifying different types of feed fluid, a test structure is required that enables rapid access to the membrane packs to enable frequent inspection and frequent trying out of different membrane packs. Furthermore, low cost dynamic seals which prevent leakage of fluids often need replacement. A rotary purification apparatus which enabled rapid access to the chamber which holds membrane packs or the like, and to dynamic seals, would be of considerable value, particularly in test rotary apparatus, but also in some smaller commercial rotary apparatus for producing fluids that are commercially used.